This dissertation deals with the insertion of the design(er) in the editorial production of the textbook – an instrument which is widely used in education in Brazil and, generally, acts as a foundation outlining the teaching practices applied in the classroom –, with a focus on the use of the geography textbook in elementary education. Among other issues, the question that guides this work can be summarized into the following: what is the role of design(er) in the textbook editing process? The collective construction process which the work goes through suffers interference from many different sources, making it much more difficult to define beforehand the roles and the limits imposed on the designer. However, it is possible to confirm the importance of the role of the designer in the production chain, being reasonable to assume that the designer even has a social role in this process. From this conjecture it is possible to delineate the path that leads to the issues facing this question. It is therefore an investigation – through a case study which examines the editorial production process – considering the role and the involvement of the agents present in the production chain (especially the designer), highlighting their functions, limits, and possible contributions. Finally, this observation allows us to examine the real and the idealized functions of the main participants in this process – such as the designer, one of the mediating reading agents –, taking into account the particularities of the production chain of textbook publishing, which is guided by a policy with precise objectives and educational and pecuniary interests.